sounds, menu tweaks

2026-07-16 10:42:57 +02:00
parent 88922bd932
commit f2bf6ba6ad
5 changed files with 174 additions and 9 deletions
@@ -0,0 +1,135 @@
+; -----------------------------------------------------------
+; sound.asm - minimal SID sound driver using voice 1
+;   sfx_init  - set master volume, silence voice 1
+;   sfx_play  - start effect A (SFX_SCORE, SFX_MISS, etc.)
+;   sfx_update - call once per frame to handle duration/slides
+; -----------------------------------------------------------
+
+; ---- one-time setup: master volume on, voice 1 silent ----
+sfx_init:
+    lda #$0f             ; max volume, no filter
+    sta SID_VOL
+    lda #0
+    sta SID_V1CR         ; gate off, no waveform
+    sta sfx_timer
+    rts
+
+; ---- start playing effect A ----
+sfx_play:
+    tax
+    ; gate off first (retrigger envelope)
+    lda #0
+    sta SID_V1CR
+    ; load parameters from the table
+    lda sfx_flo,x
+    sta SID_V1FL
+    lda sfx_fhi,x
+    sta SID_V1FH
+    lda sfx_ad,x
+    sta SID_V1AD
+    lda sfx_sr,x
+    sta SID_V1SR
+    lda #$00             ; pulse width mid-point for pulse wave
+    sta SID_V1PL
+    lda #$08
+    sta SID_V1PH
+    lda sfx_wave,x       ; waveform + gate bit
+    sta SID_V1CR
+    lda sfx_dur,x
+    sta sfx_timer
+    lda sfx_slide,x
+    sta sfx_sld
+    rts
+
+; ---- per-frame update: pitch slide + gate off when done ----
+sfx_update:
+    lda sfx_timer
+    beq sfu_done          ; nothing playing
+    dec sfx_timer
+    bne sfu_slide
+    ; duration expired: gate off
+    lda #0
+    sta SID_V1CR
+    rts
+sfu_slide:
+    ; apply pitch slide (signed: positive = up, negative = down)
+    lda sfx_sld
+    beq sfu_done
+    bmi sfu_down
+    ; slide up
+    clc
+    adc SID_V1FH
+    sta SID_V1FH
+    rts
+sfu_down:
+    ; slide down (sfx_sld is negative, e.g. $fe = -2)
+    clc
+    adc SID_V1FH          ; adding a negative = subtracting
+    sta SID_V1FH
+    bcs sfu_done          ; no underflow
+    lda #0
+    sta SID_V1FH          ; clamp at zero
+sfu_done:
+    rts
+
+; ---- effect parameter tables (indexed by SFX ID) ----
+
+; initial frequency low byte
+sfx_flo:
+    !byte $00             ; SFX_SCORE:  freq $1C00
+    !byte $00             ; SFX_MISS:   freq $0800
+    !byte $00             ; SFX_OVER:   freq $2000
+    !byte $00             ; SFX_CURSOR: freq $0A00
+    !byte $00             ; SFX_SELECT: freq $1000
+
+; initial frequency high byte
+sfx_fhi:
+    !byte $1c             ; SFX_SCORE
+    !byte $08             ; SFX_MISS
+    !byte $20             ; SFX_OVER
+    !byte $0a             ; SFX_CURSOR
+    !byte $10             ; SFX_SELECT
+
+; attack/decay ($XY: X=attack 0-F, Y=decay 0-F)
+sfx_ad:
+    !byte $00             ; SFX_SCORE:  instant attack, instant decay
+    !byte $00             ; SFX_MISS:   instant attack, instant decay
+    !byte $09             ; SFX_OVER:   instant attack, slow decay
+    !byte $00             ; SFX_CURSOR: instant attack, instant decay
+    !byte $00             ; SFX_SELECT: instant attack, instant decay
+
+; sustain/release ($XY: X=sustain 0-F, Y=release 0-F)
+sfx_sr:
+    !byte $a8             ; SFX_SCORE:  medium sustain, medium release
+    !byte $f5             ; SFX_MISS:   full sustain, medium release
+    !byte $08             ; SFX_OVER:   zero sustain, medium release
+    !byte $50             ; SFX_CURSOR: low sustain, instant release
+    !byte $98             ; SFX_SELECT: medium sustain, medium release
+
+; waveform + gate ($XY: bit7=noise, bit6=pulse, bit5=saw, bit4=tri, bit0=gate)
+sfx_wave:
+    !byte $11             ; SFX_SCORE:  triangle + gate
+    !byte $81             ; SFX_MISS:   noise + gate
+    !byte $21             ; SFX_OVER:   sawtooth + gate
+    !byte $41             ; SFX_CURSOR: pulse + gate
+    !byte $11             ; SFX_SELECT: triangle + gate
+
+; duration in frames
+sfx_dur:
+    !byte 8               ; SFX_SCORE
+    !byte 10              ; SFX_MISS
+    !byte 50              ; SFX_OVER
+    !byte 3               ; SFX_CURSOR
+    !byte 8               ; SFX_SELECT
+
+; pitch slide per frame (signed: + = up, - = down, 0 = none)
+sfx_slide:
+    !byte 0               ; SFX_SCORE:  steady
+    !byte $fe             ; SFX_MISS:   slide down (-2)
+    !byte $fd             ; SFX_OVER:   slide down (-3)
+    !byte 0               ; SFX_CURSOR: steady
+    !byte 2               ; SFX_SELECT: slide up (+2)
+
+; ---- driver state ----
+sfx_timer: !byte 0        ; frames remaining for current effect
+sfx_sld:   !byte 0        ; current slide value